Looking for advice on a road bike fit, with a mind to racing. I’ve been advised I look cramped and my breathing would benefit from adding some length to my stem. I certainly find it hard to get my head inline with my body and feel a tad cramped, though when relaxed and upright the position feels great. Should I try 10mm more? 20mm?
Your position isn’t bad, actually, but could definitely stand to get stretched out a bit more. Your hip rotation looks pretty good, so if you can get stretched out more, you stand a good chance of getting more aero.
What length stem are you currently running?
Thanks for responding, it’s currently 100mm. I had already planned to try 110, but would 120 be a more worthwhile shot? I currently sit on the hoods permanently, no issue of wanting to be on the tops, and when I get aero with bent elbows I feel the lack of room.
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I usually advocate smaller changes vs big ones…so I would start with the 110 and see how it looks / feels.
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Does anyone have any ideas on this? I have been riding an SL7 for the last couple of years but recently tried out a Dogma F. 52cm SL7 and 51.5cm Dogma. Setup with the same saddle nose to hood length and seat to middle crank.
The Dgoma feels way less stretched and now I think the SL7 is wrong. I want to sit on the tops on the SL7 compared to the hood on the Dogma. Is there anything i can do to my SL7 to make it feel more like the Dogma i tried or is it purply just a completely different geo that maybe fits me better?
It sounds like a measurement issue. The contact points are just points in space, geometry will affect the way it handles.
Ideally, you’d separate out the X & Y components of the position to check that they’re identical.
What’s the comparative bar height like? Is it the same saddle?
Measuring from BB centre to top of the saddle can be skewed if the seat angle differs and you’re measuring in line with the seat tube. Commonly saddle top is measured to an 80mm width point.
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Same saddle yes.
I measured from nose of saddle to middle BB on both. Looking at the geo online it seems to say the Dogma has a higher front end (stack) and shorter reach. SO i guess this affects the measurement of nose saddle to hoods even if its the same the angle could be different.
You need to measure the vertical drop from the top of the saddle to the top of the hoods. I am guessing you have a different drop even of you match the horizontal reach.
Yeah i think there will be a different drop, looking at the geometer measurements. Whats the easiest way to measure it? Once i find the difference what can i do to the SL7 to make it nearer? Handlebars higher?
Pardon the quick MS Paint hack:
- Make sure the bike is on level ground (in a trainer or leaning on a wall),
- Use a long level, resting on the nose or center of the saddle,
- Then use a tape measure or ruler to capture the vertical space between the bottom side of the level and top of the hoods where your hands rest.
- This is your Hood Drop. Repeat and compare between any bikes of interest. Use this data along with your other dimensions for a complete comparison of the actual fit measurements.
ETA, here is a snapshot of the fit sheet I commonly use for my fits and own tracking. I keep this full data for every bike I own, so I can compare them and/or reset dimensions as needed if something changes.
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So it appears the SL7 has 0.5 - 1cm greater drop. I guess this is the reason for feeling more stretched then?
Yup, that would do it. Assuming your position from BB to the saddle is identical, and even with the linear reach to the drops the same, this greater drop can be enough to be uncomfortable on the lower one.
- It depends a lot on how close to the edges you are on the higher setup; in terms of body position, back shape, arm stretch, head angle and the like.
- If you are at the fringe of one or move of those adding 5-10mm of drop can push you over the edge.
If you have enough steer tube on the lower setup, adding 10mm of spacers under the stem is a quick way to alter the fit and see if it solves the issue (both by redoing measurements, as well as actual rider on the revised setup).
If you don’t have the option for spacers under the stem, and presuming you have a stem with a negative angle as installed right now, you can flip the stem over and evaluate. This single change (assuming no other alteration) will raise the bars higher, but also pull them a bit closer to you.
Here is one example using a 6* x 100mm stem flipped:
Yeah makes sense, worth a go. I didn’t build this one so fingers crossed i can slip another 10mm in there with no issues!
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Just in case you don’t know, it’s common wisdom (if not MFGR required) to have at least 2.5-5mm of carbon steer tube ABOVE the top edge of the stem (and using a proper height shortie spacer). This is about retaining enough material to prevent crushing the carbon steer tube.
It can get more complicated than this when you dive into the preload component in the tube, so make sure you do the safe and proper setup. I’ve seen too many people hang a stem higher than the steerer. Even if they “get away” with it, they are taking an unnecessary risk.
/PSA
Yeah yeah i know you need a bit of a gap. Just hoping adding 10mm doesn’t create to much of a gap. We shall see!
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Cheers @mcneese.chad I had a lengthy bike fit this afternoon so couldn’t jump back into the conversation to assist @Dunk more.
I’d recommend one of these tools for anyone with an interest in their bike position and a few bikes. Perhaps buy one in a club or group and share it. They’re not expensive and help deal with the issue above.
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I actually bought two of these. I love the concept but think they missed on a few details. I have an active design project in motion to make some new 3D printed parts to work more like I want this tool to function. I do like the potential in this tool, and hope to get there with my mods.
Outside of that, a tape measure and level work well, having have served me fine in hundreds of fits in the shop and at home over 10 years.
I’ve bought one and loan it to my customers who come in to get a position for their Wattbike. Wattbike do a poor job of assisting their customers to replicate their road position on their indoor rig. They should supply one of these with each bike sold.
Customer feedback on its use is very positive.
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The concept is solid and I am happy to have them. I am just picky, and want to add some functionality right into the tool.
- Bubble levels for horizontal and vertical alignment
- Better “center to center” measurements with internal and external round contacts
- Better distance indication than their hard line and fully hidden side vs open window.
Top View:
Front view:
I also want to make an adapter for the short measurement of bar drop and saddle setback. Goal to eliminate the need to us any separate tool for all bike fit measurements.
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I had to RMA my Tacx Bike as the chain broke, and since its return, I cannot pinpoint where the fit isn’t right. Getting really bad lower back pain and Quads BURNING. There’s some slight pressure on my hands when I am on the drops.
Any suggestions where to look? I’ve used a standard tape measure against my Specialized Roubaix, the that look out are saddle needs to come forward about 10mm, and the Saddle to handle bar drop needs about 40mm drop. I feel like that will put more pressure on my hands?